The Battle of Chongju was one of the first Korean victories on land during the Imjin War. Also, it was won by the Korean irregular volunteers that included Buddhist warrior monks as well.

Jo Heon, one of the most well known Korean irregular leaders, along with Hyujong, who led the Buddhist forces decided to attack Chongju. Chongju was captured by the Third Division of the Japanese army under Kuroda Nagasama in the opening battles of the Imjin War.
Chongju was important because it provided as an important center for transporting supplies to Japanese forces in the north. Also, Chongju was one way to Hanseong (Seoul). Chongju was under the general of Hachisuka Iemasa (1558-1638).
With information that it was lightly guarded, the Korean irregular army decided to recapture Chongju from the Japanese. Capturing Chongju would cut Japanese communication lines and provide a stepping stone to southern Korea where the invasion of Jeolla Province could be stopped.
[edit]Battle of Chongju

The Korean irregular forces attacked Chongju, bringing ladders on all the gates. Fierce melee fighting ensued and both sides lost soldiers. Hachisuka finally forced the Koreans to retreat after fire from arquebuses, which the Koreans were terrifed of. Hachisuka believed the Koreans were gone. No more attempts to attack Chongju was made.
Instead, Jo Heon took several soldiers to a hill and lit many fires on stakes. The Koreans set up flags as well. This was done at night, and the Japanese were completely fooled into believing that the Korean army was very large. Hachisuka immediately retreated from Chongju. The Korean irregulars marched into Chongju with a victory. This also boosted the morale of the surrounding Korean forces in the area as well since this was one of the first land victories for the Koreans.
[edit]Aftermath

Despite the victory, Korean irregular leaders argued over the credits for the battle and relationships between the Buddhist monks and irregulars fell. With Chongju secured, Korean forces were able to attack Japanese positions but failed. The internal fighting led to the defeat and total annihilation at Kumsan.